An assize court is like a big people’s court where important cases are heard by judges and a jury, which is a group of regular people who listen to the evidence and make a decision about who is right or wrong. The cases in an assize court are usually really serious, like someone being accused of a really bad crime, and the decision made by the judge and jury can have a big impact on the person’s life.
The word “assize” comes from old French and means “to sit”. So the judges and jury “sit” in this big court to hear the cases. This court used to be very important in England a long time ago, but now it’s not used as much anymore.